Datasheet

1203
SAM4E [DATASHEET]
Atmel-11157D-ATARM-SAM4E16-SAM4E8-Datasheet_12-Jun-14
And for a successful match to the type ID, the following Type ID Match 1 Register must be set up:
Type ID Match 1 Register (GMAC_TIDM1) (Address 0x0A8) 0x80004321
43.5.8 Broadcast Address
Frames with the broadcast address of 0xFFFFFFFFFFFF are stored to memory only if the 'no broadcast' bit in the
Network Configuration Register is set to zero.
43.5.9 Hash Addressing
The hash address register is 64 bits long and takes up two locations in the memory map. The least significant bits
are stored in Hash Register Bottom and the most significant bits in Hash Register Top.
The unicast hash enable and the multicast hash enable bits in the Network Configuration Register enable the
reception of hash matched frames. The destination address is reduced to a 6-bit index into the 64-bit Hash
Register using the following hash function: The hash function is an XOR of every sixth bit of the destination
address.
hash_index[05] = da[05] ^ da[11] ^ da[17] ^ da[23] ^ da[29] ^ da[35] ^ da[41] ^
da[47]
hash_index[04] = da[04] ^ da[10] ^ da[16] ^ da[22] ^ da[28] ^ da[34] ^ da[40] ^
da[46]
hash_index[03] = da[03] ^ da[09] ^ da[15] ^ da[21] ^ da[27] ^ da[33] ^ da[39] ^
da[45]
hash_index[02] = da[02] ^ da[08] ^ da[14] ^ da[20] ^ da[26] ^ da[32] ^ da[38] ^
da[44]
hash_index[01] = da[01] ^ da[07] ^ da[13] ^ da[19] ^ da[25] ^ da[31] ^ da[37] ^
da[43]
hash_index[00] = da[00] ^ da[06] ^ da[12] ^ da[18] ^ da[24] ^ da[30] ^ da[36] ^
da[42]
da[0]
represents the least significant bit of the first byte received, that is, the multicast/unicast indicator, and
da[47]
represents the most significant bit of the last byte received.
If the hash index points to a bit that is set in the Hash Register then the frame will be matched according to whether
the frame is multicast or unicast.
A multicast match will be signalled if the multicast hash enable bit is set, da[0] is logic 1 and the hash index
points to a bit set in the Hash Register.
A unicast match will be signalled if the unicast hash enable bit is set, da[0] is logic 0 and the hash index points to
a bit set in the Hash Register.
To receive all multicast frames, the Hash Register should be set with all ones and the multicast hash enable bit
should be set in the Network Configuration Register.
43.5.10 Copy all Frames (Promiscuous Mode)
If the Copy All Frames bit is set in the Network Configuration Register then all frames (except those that are too
long, too short, have FCS errors or have GRXER asserted during reception) will be copied to memory. Frames
with FCS errors will be copied if bit 26 is set in the Network Configuration Register.
43.5.11 Disable Copy of Pause Frames
Pause frames can be prevented from being written to memory by setting the disable copying of pause frames
control bit 23 in the Network Configuration Register. When set, pause frames are not copied to memory regardless
of the Copy All Frames bit, whether a hash match is found, a type ID match is identified or if a destination address
match is found.